220v Floor outlet in workshop?

[Sam Dotson]

I am turning a 2-car garage in my new home (in Texas) into a workshop. I am finalizing my electrical plan for a sub panel and several 110 and 220 circuits, and I'm wondering if there is a "code correct" way to install a 220 circuit flush mount in the floor. Sine I don’t have a basement, and my shop floor is cement, I am adding a wood floor over the slab by laying pressure treated 2x4's on the cement (attached with glue and nails), then 6-mil plastic sheeting, and then 3/4" ply wood over that. This should give 2 1/2 inches for conduit and an electrical box. Assuming I have the room under the floor, what does the code say about this?

Sam

[Chris Damm]

How are you going to keep dust out of the outlet?

[Sam Dotson]

I'm assuming the plug that is plugged into it will do that whan something is plugged in. When nothing is plugged in, I'm assuming I can find a recepticle with a spring loaded or screw-in cover.

Notice all the assumptions? That's why I am posting here.

Sam

[Todd Burch]

IIRC, fire code disallows a wood floor in a garage built for parking cars.

[Todd Burch]

On another note - a 2 car garage is not that big. Why not just a longer power cord? Will the machine be in a fixed place? If so, I would stub out a short receptacle to be positioned up inside cabinetry or other enclosure that is part of the fixed machine.

Todd

[Joe A Faulkner]

Search for recessed brass outlet boxes or recessed outlet boxes.

Here's one example: http://www.acehardwareoutlet.com/pro...?sku=998003692

You will note these are expensive, but they are designed to be recessed in a floor and provide for some "crush resistence". Seems like this shoudl work for a 20 amp outlet.

I was considering these a while back for my shop remodel. I've since backed off on the idea of putting in the wooden floor for two reasons: 1: materials alone would run me about $800 and I have to weigh that against or lets see, a tablesaw upgrade, a bandsaw, a lathe, a workbench and decided I'd just buy better quality shoes for the shop. 2: While I don't have any immediate plans to move, it isn't out of the question and I'm not sure the wooden floor would be as valuable to a buyer as it is to me.

[Sam Dotson]

IIRC, fire code disallows a wood floor in a garage built for parking cars.

Once the wood floor is installed, it would be intended for parking cars any longer. Surely just because it was built for parking cars, this doesn’t mean I can’t put down a wood floor and use it for something else.

Sam

[Sam Dotson]

Thanks Joe, I will check out that outlet box.

The wood floor is more to protect dropped hand tools (like planes and chisels) and to allow floor mounted power for tools in the middle of the floor than to protect my feet. I have another three car garage for parking, so I’m hoping the wood floor would be an issue for a potential future buyer. If it turns out to be, I can always remove the floor I guess

Thanks


Sam

[Luther Oswalt]

Once the wood floor is installed, it would be intended for parking cars any longer. Surely just because it was built for parking cars, this doesn’t mean I can’t put down a wood floor and use it for something else.

Sam

I would check with your local codes office because it is not just wether it is in the fire code the codes folk and tax folk may come calling on you. That's a sure thing if you are building and have a permit.

[Richard Jones]

IIRC, fire code disallows a wood floor in a garage built for parking cars.

Code here in VA doesn't allow a wood floor in a garage, but this will no longer be a garage. Wouldn't be a problem in my jurisdiction, have done quite a few like this.

Also, floor boxes must be rated, listed and labeled for the intended use.

Rich

[Thom Porterfield]

The problem I have with floor boxes is that they're not always in the right place...and then you have extension cords again. To solve that problem in my shop I put in trenches instead. Granted, my floor is a concrete slab, but my solution (following) shouldn't be that difficult to implement in a wood floor.

What I did was install 4" x 4" x 12' trench drains, but I replaced the slotted covers with sheets of plywood. I can make those covers any length I want (up to 8' long) and put a power cord-sized hole at whatever location is convenient for my tools. My shop is 18 feet square, approximately, and I have two such trenches parallel to one another, 4' apart in the center of the room. I installed 2" conduit pull chases under the slab to the wall where the service panel is located and each terminates in a junction box. I can run non-metallic cable to either trench and locate a junction box and receptacle for either 110 or 220 power. Then the pigtail from the tool need only drop into the trench through the cover. As it happens, my table saw, jointer and router table sit directly over one or the other trench and there are no cords laying about on the floor.

I suppose, if I wanted to, I could install a floor outlet, such as described above, in the plywood, but I haven't yet found the need.

[Dan Hintz]

I would not want to spill any liquids near a surface-mount outlet...

[Joe Angrisani]

Sam... Where will the dust collection be coming from? I'm in the "no floor outlet in a dusty environment" camp, so I'd suggest bringing the power down from the ceiling along with the dust collection ductwork. If the ductwork will just come across the floor, I'd run the saw's power cord through one of those "no trip" strips in the same area as the dust ductwork (if you have to step over a duct, you'll never notice a power cord coming through in the same place).

[Rob Russell]

Sam,

Because you're installing a raised floor, I would run conduit under the floor and feed a surface mounted subpanel. From that subpanel, you can run whatever you want for circuits in surface-mounted conduit. That's all easily removeable when you sell the house and gives you the flexibility to add circuits as you need.

Rob

[Sam Dotson]

Sam... Where will the dust collection be coming from? I'm in the "no floor outlet in a dusty environment" camp, so I'd suggest bringing the power down from the ceiling along with the dust collection ductwork. If the ductwork will just come across the floor, I'd run the saw's power cord through one of those "no trip" strips in the same area as the dust ductwork (if you have to step over a duct, you'll never notice a power cord coming through in the same place).

That's a good point Joe, since there should be a dust collection run to every "island" in the workshop, I will consider ceiling mounted outlets with twist lock cords dropping down beside the dust collection run.

Thanks!